As a former BritMil pilot who's done similar - and who hasn't? (4-ship doors-open flybys along German nudist beaches, 6 time a day for a fortnight - it paled after a while but the troops enjoyed the show), my sympathies are with the crew. Sadly, as we have seen, the Internet we've come to know and love sometimes bites back.
If anyone on the receiving end of the gesture had complained, I'd have been surprised, given the nature of the audience. A boot up the back-side/quiet word/slab should have sufficed. What disappoints me most is that someone up the chain-of-command lacked the cahonas to stop this before it got out of hand.
A large part of my life was spent ensuring that we maintained the rights of democracy - including the freedom to speak one's mind, so long as one had the strength of character and the courage to defend one's actions.
As one Billy Connolly succinctly put it "Political correctness is the language of cowardice".